1. Field of the Invention
The present invention relates to a disc processing apparatus for processing disc cartridges (including recording mediums such as optical discs or magnetic tapes) arranged on storage locations for a drive unit.
2. Description of the Prior Art
An example of a prior art disc processing apparatus for automatically changing disc cartridges containing optical discs is shown in FIGS. 1(a) to (c), which has been disclosed by the same applicant and which bears Japanese Published Examined (Kokoku) Utility Model Application No. 4-22441.
With reference to the drawings, the prior art disc processing apparatus is composed roughly of a plurality of storage locations 102 arranged in parallel to each other in the vertical direction, for housing disc cartridges 101; a plurality of drive units 103 each for recording and reproducing information data to or from an optical disc housed in each disc cartridge 101; and a vertical carrier 104 disposed in front of the storage locations 102 and the drive units 103. The vertical carrier 104 is so constructed as to be movable in the vertical direction along a guide rail 105 by a driving belt 106. Further, the vertical carrier 104 is provided with a grip mechanism 107 (see FIG. 1(b)) for gripping disc cartridges 101. The vertical carrier 104 can be turned over upside down about a reversal axle 108.
In the above-mentioned prior art apparatus, the disc cartridges 101 can be carried and changed between the storage locations 102 and the drive units 103 with the use of the vertical carrier 104, there exist problems in that it takes a relatively long disc change time and further a relatively large space is inevitably required.
In more detail, the disc cartridges 101 are changed in accordance with the following steps: (1) the vertical carrier 104 is moved in the vertical direction to a designated storage location 102 on which a designated disc cartridge is laid; (2) the designated disc cartridge 101 on the designated location 102 is held by the grip mechanism 107 of the vertical carrier 104; (3) the vertical carrier 104 which holds the designated disc cartridge 101 is moved vertically to a designated drive unit 103; (4) the disc cartridge 101 is loaded onto the designated drive unit 103 with the grip mechanism 107 for writing and/or reading operations; (5) another disc cartridge 101 already used by another drive unit 103 is held by the grip mechanism 107 of the carrier 104; (6) the vertical carrier 104 is moved to a storage location 102 on which the used disc cartridge 101 has been laid; (7) the used disc cartridge 101 is returned to the home location 102 with the grip mechanism 107.
As described above, since there are a large number of steps due to the rather complicated operation, it is difficult to reduce the time required for changing the disc cartridges 101.
In addition, since there exists a large dead space between the vertical carrier 104 and the storage locations 102 or the drive unites 103, in order to carry and change the cartridges, the space factor is low and therefore there is a limit by which the total size of the disc processing apparatus has to be reduced.